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Finding the Fourth Proportional to 439.92, 659.28 and 426.78

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Solution

The fourth proportional to 439.92, 659.28 and 426.78 is: 639.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    439.92 : 659.28 = 426.78 : x
  2. Step 2: Convert to fraction form
    439.92/659.28 = 426.78/x
  3. Step 3: Cross multiply
    439.92x = 659.28 × 426.78
  4. Step 4: Simplify right side
    439.92x = 281,367.52
  5. Step 5: Solve for x
    x = 281,367.52/439.92
  6. Step 6: Final answer
    x = 639.59

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.